DE202012013102U1 - Medical device - Google Patents

Abstract

Medical device having a tubular, tubular or hollow needle-shaped body or in the form of such a body, which consists of layers (12, 14, 16), with a first layer (12) made of plastic and an adjacent second layer (14) made of plastic in that at least in the second layer hollow spheres (22, 24) for generating echogenic properties are contained, characterized in that both the first layer (12) as inner layer and the adjacent second layer (14) comprise hollow spheres (18, 20, 22 , 24) for generating echogenic properties, and in that the hollow balls (18, 20) of the first layer as the first hollow spheres have on average a smaller diameter D ₁ than the hollow spheres (22, 24) in the second layer than the second hollow spheres and / or the filling content F _{1 of} the first hollow spheres in the first layer is smaller than the filling content F _{2 of} the second hollow spheres in the second layer.

Description

The invention relates to a medical device with a tubular, tubular or hollow needle-shaped body or a form of such even with at least one inner first layer and an adjacent second layer, wherein in the second layer hollow spheres for generating echogenic properties are included.

In recent years, ultrasound diagnostics has advanced significantly as an imaging technique. As part of the control of invasive procedures in medicine, it offers a process that is harmless to the patient and that allows the doctor to intervene at the same time. The z. However, catheters currently available on the market can be safely visualized by ultrasound only at depths of a few millimeters below the surface of the skin.

In the manufacture of medical catheter tubes thermoplastically processable plastics such. As TPE, polyamide, polyurethane, polyethylene or flexible PVC used. Multilayer or composite hoses can also be used as catheter tubes to combine different materials in a tube. A special form of multilayer or composite hose are liner hoses. These hoses have one or more integrated strips. The stripes can be pure color stripes or functional stripes such. B. Röntgengenkontraststreifen act.

Also multi-lumen tubes are known which have a plurality of parallel tubes. These find in medical technology another field of application, be it as an infusion catheter, be it as supply hoses or multifunctional hoses.

Furthermore, fabric-reinforced hoses or hoses with extruded wires / data lines are known. To z. B. sensors or electrodes to contact it is known to extrude electrical lines in the walls of a catheter tube.

When conducting diagnostic and therapeutic interventions, accompanying imaging techniques are used to control or correct the position of the catheter during the procedure. For this purpose, the X-ray is often used to determine the position of the catheter. Since pure plastic catheters are difficult or impossible to localize by X-ray, the previously discussed liner tubes are used. X-ray methods, however, show, in addition to the radiation, the disadvantage that locating the catheter during the procedure is not readily possible, since these are temporally and locally decoupled processes.

On the other hand, ultrasound diagnostics offer the possibility of tracking the process with simultaneous intervention by the physician without damaging the patient. However, the catheters currently used have little echogenicity, both in construction and in the materials used; H. Ultrasound visibility on.

The echogenicity essentially depends on the sound-reflecting property of the respective structure. The visibility in the ultrasound is based on the difference of the product of density and speed of sound between on the one hand the tissue and on the other side of the object to be detected such as catheters.

To increase the echogenicity in all metallic objects such as needles, different methods are known, which are usually concerned with the mechanical modification of the geometry of the needle or needle tip. Roughening, faceting or similar measures are known. The coating of the surface of metallic objects is also used. In doing so, scattering and reflection centers are embedded.

From the DE-U-20 2009 001 974 is an echogenic coating of a catheter known. This consists of a polymer with embedded hollow microspheres, which in turn can be filled with gas such as isobutane. The hollow spheres themselves can z. B. consist of vinylidene chloride. The coating can be applied by spraying.

From the EP-B-0 941 128 For example, a layer system is known that has a matrix of a polymer material, wherein compressible trapped gas bubbles form on heating, which lead to reflection of the ultrasound. In addition, a contrast agent for X-ray images can be introduced.

An echogenic surface layer after the US-A-5,383,466 contains gas bubbles in a matrix of polymer.

A medical instrument after the US-B-6,306,094 has on the outside a coating in which discrete mobile bubbles are formed in a reaction with a reactant.

A matrix with contrast - enhancing elements, which in turn change their reflection properties as a function of temperature, is known from US Pat US-B-6,749,554 known.

In the DE-A-100 50 199 A method for producing a planar implant with detectable elements is described. In producing the detectable in the ultrasound elements, a syntactic foam is extruded, in which preferably gas-filled glass bubbles are embedded.

The DE-T-693 19 632 relates to a method, apparatus and material for amplifying ultrasonic echoes. Reflective particles are embedded in a base or matrix material that encloses an elongate tube. The reflective particles and optionally an X-ray opaque material are mixed into the matrix material prior to extrusion of a catheter.

Sound-reflecting particles are after the EP-B-0 386 936 a matrix material is added before a catheter is made by extrusion.

An echogenic coating with motile gas bubbles for a catheter is known from US Pat DE-T-697 28 892 known.

Of the EP-A-2 308 551 There is a needle to block nerves. The needle has a metal tube on the inside and a layer with echogenic particles on the outside.

Of the EP-B-1 462 056 For example, reference is made to a medical device, in particular in the form of a catheter, which has at least two layers produced by extrusion, of which the outer layer is thicker than the inner layer. Gas bubbles are dispersed in the outer layer. In contrast, the inner layer is essentially free of gas bubbles. The gas bubbles can be formed by expanding polymer microsphere.

If echogenic properties are achieved by coatings, in particular by means of gas bubbles, an uneven reflection occurs as a result of the production process, since it is not possible to produce gas bubbles in uniform dimensions for optimum ultrasound reflection.

The present invention is based on the object, a device, in particular a catheter or catheter tube of the type mentioned in such a way that the echogenic properties are improved in comparison to the Stand de Terchnik to allow visualization at greater depths.

To achieve the object, the invention essentially provides that both the inner first layer and the adjacent second layer hollow spheres for generating echogenic properties and that the hollow spheres of the first layer as the first hollow spheres on average a smaller diameter than the second hollow spheres forming hollow spheres in the second layer and / or that the filling content of the first hollow spheres in the first layer is smaller than the filling content of the second hollow spheres in the second layer.

In particular, it is provided that the device has three layers, of which at least the first layer and the adjacent second layer has echogenic properties as a middle layer.

In a three-layer device, the inner first layer and the outer layer should have as the third layer a thickness D _1.3 with D _1.3 ≦ 80 μm, in particular 20 μm ≦ D _1.3 ≦ 60 μm, preferably D _1.3 in about 40 microns have.

In contrast, it is preferably provided that the second layer adjoining the inner first layer has a thickness D _{2 of} 50 μ ≦ D ₂ ≦ 150 μm.

Regardless of the thicknesses of the individual layers, the total thickness of the layers should not exceed a value of 200 μm to 300 μm.

The material of the individual layers should be identical. It should be thermoplastically processable plastics, which have biocompatible properties, use. Preferably, thermoplastic elastomers (TPE), polyamide, polyurethane, polyethylene or flexible PVC may be mentioned.

The wall thickness of the hollow spheres should be less than 10 .mu.m, with preferred values between 0.5 .mu.m and 8 .mu.m, in particular between 1 .mu.m and 3 .mu.m to call.

The filler content of the spheres in the second layer should be 2 wt% to 25 wt%, preferably between 5 wt% and 15 wt%.

In contrast, the filling content of the first layer should be less than 12%, in particular in the range between 3% and 10%.

Preferably, the ball diameters of the first layer are on average smaller than the ball diameters of the adjacent second layer. Also, the filling content of the first hollow spheres in the first layer is smaller than the filling content of the second hollow spheres in the second layer.

The hollow spheres are in particular hollow glass spheres which are filled with a gas such as O ₂ or SO ₂ . The glass bubbles should have a negative pressure, the absolute should be between 0.5 bar and 0.9 bar, in particular at about 0.7 bar.

The advantage of the use of hollow glass spheres is that they retain their shape in comparison with those made of a plastic during extrusion and the scattering, ie. H. the distribution of the diameter is within relatively narrow limits. These measures ensure that, on average, the balls in the inner layer have a smaller diameter than the adjacent second layer. However, this does not exclude that in the second layer there are some spheres which are smaller than the spheres of the first layer in the center and conversely in the first layer there are some spheres with a diameter larger than some spheres of the second layer.

Irrespective of this, provision is made in particular for the device to be produced by coextrusion of the layers. In this case, the device preferably consists of three layers, of which the inner first layer and the adjacent middle layer have, as second layer, echogenic properties of the kind previously described.

In a development of the invention, it is provided that one of the layers, in particular the echogenic layer, additionally contains an X-ray contrast medium such as barium sulfate powder. Contrast agents in strip form or sections of strips are also possible. Thus, the device according to the invention not only offers particularly good echogenic properties, but also an X-ray contrast.

Further details, advantages and features of the invention will become apparent not only from the claims, the features to be taken these features - alone and / or in combination - but also from the following description of a drawing to be taken preferred embodiment.

In the single figure is a section of a catheter tube in longitudinal section 10 shown as an example of a medical device according to the invention, the - also exemplary - three layers 12 . 14 . 16 which are preferably produced by coextrusion. The material used for each layer is a thermoplastic elastomer, in particular thermoplastic copolyamides (TPE-A).

The device may also have only two layers or four or more layers. In the inner or first layer 12 and the adjacent middle or second layer 14 are according to the teaching of the invention hollow spheres in the form of hollow glass spheres 18 . 20 respectively. 22 . 24 embedded, so that good echogenic properties arise.

The glass bubbles 18 . 20 . 22 . 24 have a negative pressure and are filled in particular with O ₂ or SO ₂ as gas. The absolute vacuum should be between 0.5 bar and 0.9 bar, in particular 0.7 bar.

Regardless of this, and in particular for optimizing the echogenic properties, it is provided that the diameters of the first layer 12 embedded glass bubbles 18 . 20 smaller than the diameter of the adjacent second layer 14 existing glass bubbles 22 . 24 is. In particular, it is provided that the diameter of the balls to be designated as the first hollow glass balls 18 . 20 in the first shift 12 is less than 25 microns, in particular between 5 microns and 20 microns, the values are mean values. The diameter of the second glass bubbles 22 . 24 that is, those who are in the adjacent second shift 14 should be between 10 μm and 80 μm, in particular between 20 μm and 50 μm, preferably between 30 μm and 40 μm.

With respect to the filling content of the first and second hollow glass spheres 18 . 20 . 22 . 24 a distinction is made in the layers such that the filling content in the first layer is less than 12%, in particular between 3% and 10% and in the second layer between 2% and 25%, in particular between 5% and 15% should.

The outer or third layer 16 and the inner or first layer 12 should have an equal thickness D _1.3 , which is in particular D _1.3 <80 microns, preferably between 20 microns and 60 microns. As a preferred value is to be stated in about 40 microns.

With regard to the middle layer, ie second layer 14 , is to indicate a preferred thickness D _{2 is} a value between 50 microns and 150 microns.

Regardless of this, the total wall thickness of the catheter should be 10 that of the lumen 26 is interspersed between 50 microns and 300 microns.

Furthermore, in one of the layers 12 . 14 . 16 a contrast agent can be introduced. So z. In the outer layer 16 Be contained barium sulfate powder. Other contrast agents are also possible, although these are not necessarily in the outer layer 16 must be present. Rather, the X-ray contrast agent in the middle layer 14 or inner layer 12 or in each of the layers 12 . 14 . 16 be introduced. Instead of powder as a contrast agent, larger particles such as strips can be co-extruded.

Due to the teaching of the invention, a mass product, in particular in the form of a catheter or catheter tube available are provided, which has good echogenic properties, wherein due to the coextrusion, a reproducibility is ensured. Due to the good echogenic properties, use in ultrasound diagnostics can be performed as an imaging procedure and used in areas that were previously closed to ultrasound diagnostics. Especially in regional anesthesia or vascular puncture precise placement of the catheter or catheter tube is guaranteed.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202009001974 [0010]
• EP 0941128 B [0011]
• US 5383466 [0012]
• US 6306094 [0013]
• US Pat. No. 6,749,554 [0014]
• DE 10050199 [0015]
• DE 69319632 T [0016]
• EP 0386936 B [0017]
• DE 69728892 T [0018]
• EP 2308551 [0019]
• EP 1462056 B [0020]

Claims (16)

Medical device having a tubular, tubular or hollow needle-shaped body or in the form of such a body, consisting of layers ( 12 . 14 . 16 ), with a first layer ( 12 ) made of plastic and an adjacent second layer ( 14 ) made of plastic, wherein at least in the second layer of hollow spheres ( 22 . 24 ) are contained for generating echogenic properties, characterized in that both the first layer ( 12 ) as inner layer as well as the adjacent second layer ( 14 ) Hollow spheres ( 18 . 20 . 22 . 24 ) to produce echogenic properties and that the hollow spheres ( 18 . 20 ) of the first layer as the first hollow spheres on average a smaller diameter D ₁ than the hollow spheres ( 22 . 24 ) in the second layer as the second hollow spheres and / or that filling content F _{1 of} the first hollow spheres in the first layer is smaller than filling content F _{2 of} the second hollow spheres in the second layer. Medical device according to claim 1, characterized in that the body ( 10 ) three layers ( 12 . 14 . 16 ), of which at least the first layer ( 12 ) and the adjacent second layer ( 14 ) has echogenic properties as middle layer. Medical device according to claim 1 or 2, characterized in that the hollow spheres ( 18 . 20 . 22 . 24 ) Are hollow glass spheres. Medical device according to one of the preceding claims, characterized in that the first hollow spheres ( 18 . 20 ) and / or the second hollow spheres ( 22 . 24 ) are each filled with a gas having a negative pressure absolutely between 0.5 bar and 0.9 bar, in particular in about 0.7 bar, wherein the gas is preferably O ₂ or SO ₂ . Medical device according to one of the preceding claims, characterized in that the first hollow spheres ( 18 . 20 ) have a mean diameter D ₁ with D ₁ ≤ 25 μm, in particular 5 μm ≤ D ₁ ≤ 20 μm. Medical device according to one of the preceding claims, characterized in that the second hollow balls ( 22 . 24 ) have a mean diameter D ₂ with 10 μm ≦ D ₂ ≦ 80 μm, in particular 20 μm ≦ D ₂ ≦ 50 μm, preferably 30 μm ≦ D ₂ ≦ 40 μm. Medical device according to one of the preceding claims, characterized in that the first and / or second hollow spheres ( 18 . 20 . 22 . 24 ) have on average a wall thickness WD with WD ≦ 10 μm, in particular 0.5 μm ≦ WD ≦ 8 μm, particularly preferably 1 μm ≦ WD ≦ 3 μm. Medical device according to one of the preceding claims, characterized in that the filling content F _{1 of} the first hollow spheres ( 18 . 20 ) in the first layer ( 12 ) F ₁ <12%, in particular 3% ≤ F ₁ ≤ 10%. Medical device according to one of the preceding claims, characterized in that the filling content F _{2 of} the second hollow spheres ( 22 . 24 ) in the second layer ( 14 ) is 2 wt .-% ≤ F ₂ ≤ 25 wt .-%, in particular 5 wt .-% ≤ F2 ≤ 15 wt .-%. Medical device according to at least claim 2, characterized in that the first layer ( 12 ) and / or in an at least three-layered device ( 10 ) an external third layer ( 16 ) has a thickness D _1.3 with D _1.3 ≤ 80 microns, in particular 20 microns ≤ D _1.3 ≤ 60 microns, preferably D _1.3 in about 40 microns. Medical device according to one of the preceding claims, characterized in that the second layer ( 14 ) has a thickness D _{2 of} 50 μm ≤ D ₂ ≤ 150 μm. Medical device according to one of the preceding claims, characterized in that the layers ( 12 . 14 . 16 ) of the device ( 10 ) have a total thickness DS with 50 μm ≦ DS ≦ 300 μm. Medical device according to one of the preceding claims, characterized in that at least one of the layers ( 12 . 14 . 16 ) contains an X-ray contrast agent. Medical device according to claim 13, characterized in that the X-ray contrast agent is barium sulfate powder. Medical device according to one of the preceding claims, characterized in that at least the echogenic layer ( 14 ), preferably each layer ( 11 . 14 ), consists of a same base material, which is a thermoplastic processable plastic, in particular a material from the group thermoplastic elastomers, thermoplastic copolyamides, polyamide, polyurethane, polyethylene, plasticized PVC. Medical device according to one of the preceding claims, characterized in that the device ( 10 ) by coextrusion of the layers ( 12 . 14 . 16 ) is made.

Images